finally solved by git config --global core.compression 9
From a BitBucket issue thread:
I tried almost five times, and it still happen.
Then I tried to use better compression and it worked!
git config --global core.compression 9
core.compression
An integer -1..9, indicating a default compression level. -1 is the zlib default.
0 means no compression, and 1..9 are various speed/size tradeoffs, 9 being slowest.
If set, this provides a default to other compression variables, such as core.looseCompression and pack.compression.